The role of radiation therapy in prostate cancer is in :
Localised disease - i.e prostate cancer that is still confined to the prostate and has not spread beyond the prostate. In this stage of the disease, the goal of treatment is a cure. Both surgery (radical prostatectomy) and radiation therapy are options in this stage of the disease. In men who are not healthy enough to withstand the stress from surgery, radiotherapy will be the preferred option. Depending on the risk of the disease, hormone therapy of varying duration may be added to increase the effectiveness of radiation therapy.
The choice between surgery or radiation therapy in this stage of the disease is a complex decision, requiring a detailed discussion of the pros and cons with the treating specialists.
Adjuvant treatment after surgery - Sometimes after radical prostatectomy, features of unfavourable diseases are found on the removed prostate, such as positive margins (cancer found at the edge of the removed specimen) or spread beyond the prostate into the seminal vesicles. These features predict an increased risk of cancer recurrence. In these cases, it is an option for radiotherapy to the pelvis to reduce the risk of cancer recurrence. The dose of adjuvant radiotherapy is less than that for treating localised disease.
Locally advanced disease - prostate cancer that has spread beyond the prostate into the surrounding tissue or pelvic lymph nodes. If the extent of spread is beyond the limits that surgery can treat the disease, radiotherapy with hormonal therapy may be the preferred option.
Salvage after surgery - some men who have had a radical prostatectomy are later found to have a recurrence of cancer either based on a rising PSA or tumour deposits seen in the pelvis. This can be treated with radiation therapy to the pelvis.
Metastatic disease - a disease that has spread beyond the pelvis into the bones or other organs. This is a disease that is not curable, and the intention of treatment is to delay the progression of disease and symptoms. The mainstay of treatment in this stage of the disease is hormonal therapy which acts by depriving the cancer cells of their "fuel" and can stop the cancer cells from growing and even shrink for a period of time.
The role of radiotherapy in this advanced stage of the disease is:
- Radiation to the prostate for men with newly diagnosed metastatic cancer with a low volume of the disease has been shown to improve survival outcomes in some men.
- Radiation to the prostate is sometimes needed to treat the problem of repeated bleeding from the prostate cancer.
- Painful tumour deposits in the bones may sometimes be treated with radiation therapy to the affected bones.
